Cache::BaseCache (3)

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NAME

Cache::BaseCache -- abstract cache base class

DESCRIPTION

BaseCache provides functionality common to all instances of a cache. It differs from the CacheUtils package insofar as it is designed to be used as superclass for cache implementations.

SYNOPSIS

Cache::BaseCache is to be used as a superclass for cache implementations. The most effective way to use BaseCache is to use the protected _set_backend method, which will be used to retrieve the persistence mechanism. The subclass can then inherit the BaseCache's implementation of get, set, etc. However, due to the difficulty inheriting static methods in Perl, the subclass will likely need to explicitly implement Clear, Purge, and Size. Also, a factory pattern should be used to invoke the _complete_initialization routine after the object is constructed.

  package Cache::MyCache;

  use vars qw( @ISA );
  use Cache::BaseCache;
  use Cache::MyBackend;

  @ISA = qw( Cache::BaseCache );

  sub new
  {
    my ( $self ) = _new( @_ );

    $self->_complete_initialization( );

    return $self;
  }

  sub _new
  {
    my ( $proto, $p_options_hash_ref ) = @_;
    my $class = ref( $proto ) || $proto;
    my $self = $class->SUPER::_new( $p_options_hash_ref );
    $self->_set_backend( new Cache::MyBackend( ) );
    return $self;
  }

  sub Clear
  {
    foreach my $namespace ( _Namespaces( ) )
    {
      _Get_Backend( )->delete_namespace( $namespace );
    }
  }

  sub Purge
  {
    foreach my $namespace ( _Namespaces( ) )
    {
      _Get_Cache( $namespace )->purge( );
    }
  }

  sub Size
  {
    my $size = 0;

    foreach my $namespace ( _Namespaces( ) )
    {
      $size += _Get_Cache( $namespace )->size( );
    }

    return $size;
  }

SEE ALSO

Cache::Cache, Cache::FileCache, Cache::MemoryCache

AUTHOR

Original author: DeWitt Clinton <dewitt@unto.net>

Last author: $Author: dclinton $

Copyright (C) 2001-2003 DeWitt Clinton